The present invention relates to an automated compact disc processor including a system for checking to insure compact discs are being properly picked and placed in a printer or duplicator forming the processor. The processor may be for printing on or duplicating CDs, CD-ROMs, DVDs and similar compact discs with center holes. A sensor is provided on a robotic picker arm and is used for several disc error conditions. These include: determining whether the recorder tray is empty when commencing a recording sequence; whether only one disc has been picked for processing in each sequence and whether or not the disc that has been processed is properly picked for removal and storage.
Recording digital information on compact discs, including music, video information and the like as well as printing on the disc has been automated, as shown in application Ser. No. 10/447,503. The mechanism that is used for handling the discs is generally very reliable, but occasionally a disc will remain in the process tray that is used for recording or printing (when a previous run was interrupted, for example), and there is a potential for dropping a second disc on top of a disc already in the tray thereby damaging the drive for the tray when two discs are on the tray.
Also, there is a possibility of picking up two discs at a time from the blank disc storage bin. The blank discs are stacked one on top of the other in the bin and sometimes the discs will stick together due to static electricity, or by being pressed together without complete curing of the varnish on the discs.
Finally, another type of error that can occur is when a disc has been processed and the processor disc tray has been extended. In present recorders and duplicators, the disc recorders are standard computer components and are not designed for robotic implementation. Due to this design limitation, the recorder tray will sometimes not extend completely or come out slightly skewed. If the tray is incorrectly positioned, the picker of the robotic arm that is used for picking the discs out of the tray may be unable to engage the opening in the disc and lift the disc from the tray. The present sensor can be used to sense such an occurrence and relay this information to a controller which then resets and retries the unloading, often resulting in a successful pick. These types of errors are capable of being detected with the present invention.